Measurements

When talking about climate change, references are made to all sorts of technical terms. Here are some of them explained. Feel free to add your own.

Unit		Explanation / Description
ppmv	parts per million by volume	to measure low concentrations of chemicals. In terms of climate change, it is used to measure the level of greenhouse gases in the atmosphere.
CO2e	Carbon dioxide equivalent	Levels of greenhouse gases, in terms of CO2. See "GHGs" glossary for more information.
MtC	Megatons of carbon	a million metric tons; a billion kilograms; or 1000 billion grammes of carbon.
MtC/yr	Megatons of carbon per year	millions of carbon emitted annually
GtC	Gigatons of carbon	a billion metric tonnes
petagram	10^12 grammes	1,000,000,000,000,000 g = a billion metric tonnes
kWh	kilowatt hour; or 1000 watt-hours	a unit of energy, particularly used for electrical energy.
MPG	miles per gallon	a measurement of fuel efficiency. Be careful, as US gallons and Imperial gallons are not equal.